The invention relates to an apparatus for needling a non-woven material with a guide means for the non-woven material between a perforated base plate and a perforated stripping plate and at least one needleboard which is disposed on the side of the stripping plate averted from the base plate and is drivable in a reciprocating manner both in the needle penetration direction as well as the direction of passage of the non-woven material.
In order to increase the advance of the non-woven material it is known (DE 196 15 697 A1, EP 0 892 102 A2) to additionally provide a needleboard drive which reciprocates in the direction of passage of the non-woven material, so that the advance of the non-woven material is increased by the movement component of the needleboard in the direction of passage of the non-woven material. The needleboard movement in the direction of passage of the non-woven material during the needle engagement in the non-woven material allows a respective advance movement of the non-woven material. In the construction of the guide means for the non-woven material between a base plate opposite of the needleboard and a stripping plate disposed between the base plate and the needleboard one must take the movement component of the needles in the direction of passage of the non-woven material into account. This means that both the base plate as well as the stripping plate need to be provided with oblong holes for the needle passage which are aligned in the direction of passage of the non-woven material, which not only increases the amount of work for producing said pass-through holes but also entails the additional disadvantage that the mutual needle distance is increased at least in the direction of passage of the non-woven material and it is thus necessary to decrease the number of needles of the needleboard.
The invention is thus based on the object of providing an apparatus for needling a non-woven material of the kind mentioned above in such a way that the needles of the needleboard can be arranged in a distribution density which correspond to the higher distribution density of the needles of needleboards which are exclusively drivable in a reciprocating manner in the needle penetration direction as a result of the tight arrangement of circular needle pass-through holes in the base and stripping plate.
This object is achieved in accordance with the invention in such a way that the base plate and the stripping plate are held movably in the direction of passage of the non-woven material and can be driven synchronously with respect to the needleboard.
Since as a result of this measure a relative movement of the needleboard with respect to the base and stripping plate in the direction of passage of the non-woven material is substantially prevented, it is possible to provide both in the base plate as well as stripping plate circular pass-through holes for the needles of the needleboard in a tight arrangement which merely depends on the strength of said plates but not on the needle movement in the direction of passage of the non-woven material. This creates the conditions as apply to conventional needling apparatuses without drive in the direction of passage of the non-woven material, so that with the higher distribution density of the needles it is possible to advantageously influence not only the needleboard size but also an even needling of the non-woven material. Notice should be taken in this connection that for a respective distribution density of the needles, the base and stripping plate could also be provided with oblong holes extending in the direction of passage of the non-woven material if two or more needles pass through said oblong holes, so that again the synchronous movement of said plates with the needleboard in the direction of passage of the non-woven material can be utilized advantageously for a higher distribution density of the needles. The synchronization of the movements of the needleboard and the base and stripping plate in the direction of passage of the non-woven material need not necessarily lead to any precise correspondence of the movement components in the direction of passage of the non-woven material as long as the differences in movement as are caused by the drive do not impair the needle passage through the pass-through holes in the stripping and base plate.
In order to provide simple constructional conditions for the reciprocating drive of the base plate the base plate may be part of a carriage which is displaceably held in the direction of passage of the non-woven material, with an eccentric drive acting upon said carriage which must obviously be driven in synchronicity with the needleboard drive for the needleboard movement in the direction of passage of the non-woven material.
The stripping plate could also be held in a sliding guide means. More favorable return motion conditions can be obtained, however, when the stripping plate is held on the eccentrics of two parallel eccentric shafts which are disposed in the direction of passage of the non-woven material in front of and behind the needleboard, because in this case the stripping plate can be lifted off from the non-woven material during the return motion following the advancing motion, which facilitates the advancement of the non-woven material during the return of the guide means of the non-woven material.